Which iPhones support the apt-X codec for Bluetooth audio?
Solution 1:
No iPhone has native support for apt-X, but you can buy a dongle such as the Sennheiser BTD 300i or a similar one from Creative to enable apt-X support.
Solution 2:
Currently no iPhones support aptX, but it is supported by the Mac OS X. You can use dongles from Creative, Sennheiser or Jaybird with the iPhone to take advantage of aptX audio quality.